A scanning laser radar system and a detection method

Abstract

The present application belongs to the technical field of laser radar, and particularly relates to a scanning laser radar system and a detection method. The system comprises a sheet laser unit for emitting sheet continuous wave laser to a target object; a telescope for receiving reflected light beams after the target object interacts with the sheet continuous wave laser; a surface array camera for imaging the light beams received by the telescope, the surface array camera being provided with a set number of rows in a vertical detection direction; a support frame for fixing the sheet laser unit, the telescope and the surface array camera; and a scanning platform for moving the support frame as a whole. The present application has the advantages that the system can cover a larger elevation field of view in a single measurement, thereby improving efficiency, and in addition, under a set detection requirement, mechanical equipment for the elevation angle is reduced, thereby reducing design cost.

Description

Technical Field

[0001] This invention belongs to the technical field of lidar, and particularly relates to a scanning lidar system and detection method. Background Technology

[0002] As an active remote sensing method, lidar is playing an increasingly important role in meteorology, environmental protection, and the detection of low-speed, small targets. However, conventional lidar has a relatively small laser emission angle and receiving field of view. Therefore, when detecting large-area objects, such as covering a 360° (horizontal) x 20° (elevation) area, conventional lidar often falls short. Although conventional lidar can be deployed on a one-dimensional or two-dimensional turntable, its inherently small field of view results in very low detection efficiency in specific application scenarios. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a scanning lidar system and detection method, the specific technical solution of which is as follows:

[0004] A scanning lidar system, comprising:

[0005] A sheet laser unit is used to emit sheet-shaped continuous wave lasers toward a target object;

[0006] A telescope is used to receive the reflected beam of light after the target object interacts with the sheet-like continuous wave laser.

[0007] An area array camera is used to image the beam received by the telescope, and the area array camera has a set number of rows in the elevation detection direction;

[0008] Support frame, used to fix the plate laser unit, telescope and area array camera;

[0009] The scanning platform is used to move the support frame as a whole.

[0010] Specifically, the positional relationship of the sheet laser unit, the telescope, and the area array camera mounted on the support frame satisfies the following: the object plane where any laser beam generated by the sheet laser unit is located, the plane where the telescope is located, and the image plane where the area array camera is located intersect at a point, satisfying the Saxony imaging principle.

[0011] Specifically, the angle of the sheet-like continuous wave laser emitted by the sheet laser unit in the vertical direction is not less than the field of view angle in the vertical direction formed by the area array camera and the telescope.

[0012] Specifically, the scanning platform is a horizontal rotating platform or a horizontal linear moving platform.

[0013] Specifically, the system also includes a data processing and control unit and a filter; the filter is used to filter out background light received by the telescope that is not of the same wavelength as the sheet laser; the data processing and control unit is connected to the controlled end of the area array camera, the sheet laser unit, and the scanning platform, respectively; the data processing and control unit is used to read and process the image of the area array camera, and at the same time control the opening and closing of the sheet laser unit and control the scanning platform.

[0014] This application also discloses another inventive concept, a scanning lidar detection method, comprising:

[0015] By using the known spatial location of the target object at multiple pitch angles and its corresponding pixel position information on the area scan camera, the relationship between the pitch angle of the imaging field of view and the row index in the image acquired by the area scan camera is established; by using the known distance information of the target object and its corresponding pixel position information on the area scan camera, the relationship between the target distance and the column index in the image acquired by the area scan camera is determined.

[0016] Read the two-dimensional image Q(x,y) generated by the interaction between the target object and the sheet-like continuous wave laser at a certain moment, which is acquired by the area array camera, where x=1:N, y=1:M, and N and M correspond to the two-dimensional image having N rows and M columns, respectively;

[0017] Based on the calibration information, the lidar signal p(a,z) with an arbitrary elevation angle a is obtained from the two-dimensional image Q(x,y), where a = A:B, z = C:D, A and B correspond to the initial and final values ​​of the elevation angle, respectively; C and D correspond to the minimum and maximum values ​​of the detection distance, respectively.

[0018] Threshold processing is performed on the lidar signal p(a,z), and combined with the position information of the scanning platform, the azimuth, elevation and distance information of the target are obtained;

[0019] By combining the lidar equation, the lidar signal p(a,z) is processed, and the atmospheric extinction coefficient profiles for different pitch angles within the pitch angle range A to B are obtained by combining the position information of the scanning platform.

[0020] Further, obtaining the atmospheric extinction coefficient profile within the angular range of pitch angle A to B includes: obtaining the atmospheric extinction coefficient profile for different pitch angles within the angular range of pitch angle A to B according to the following formula:

[0021]

[0022] Among them, z m Let H(a,z) be the reference point, located between the minimum and maximum detection distances C and D. The boundary value at the reference point is H(a,z). m );z mThe value is continuously updated based on the abrupt change position of the lidar signal p(a,z), and the boundary value H(a,z) is... m) The slope is obtained using the piecewise slope method.

[0023] Furthermore, based on the calculated atmospheric extinction coefficient profiles at different pitch angles, the following is also included:

[0024] The atmospheric transmittance at different pitch angles is obtained by calculating the atmospheric extinction coefficient profile, and the spatial location information of the atmospheric pollution emission source is determined by the atmospheric extinction coefficient profile.

[0025] Furthermore, obtaining atmospheric transmittance at different pitch angles using the calculated atmospheric extinction coefficient profile includes: obtaining the atmospheric transmittance at different pitch angles using the calculated atmospheric extinction coefficient profile according to the following formula:

[0026]

[0027] Furthermore, after calculating the target information at different pitch angles, it also includes:

[0028] The scanning platform moves a certain distance, detects the next azimuth angle, updates the target information, and returns to read the two-dimensional image Q(x,y) generated by the interaction between the target and the sheet-like continuous wave laser at a certain moment, until all target information within the target range is obtained.

[0029] The advantages of this invention are:

[0030] (1) This system can cover a large pitch field of view in a single measurement, thereby improving efficiency. In addition, under the set detection requirements, the mechanical equipment for pitch angle is reduced, thereby reducing the design cost. Furthermore, the optomechanical linkage in the pitch angle direction is reduced, thereby improving the measurement accuracy.

[0031] (2) The vertical angle of the laser unit is not less than the vertical field of view of the combination of the array camera and the telescope, which ensures that the information of the target object obtained by the laser radar is maximized each time and improves the detection efficiency of the target object.

[0032] (3) The scanning platform moves intermittently by a set distance. This method can ensure that detection is performed intermittently and then moved after detection is completed. This ensures the accuracy of the detection data while enabling regional scanning and detection, or even 360° all-round detection.

[0033] (4) The detection method of the lidar system described above can not only search and discover low, slow and small targets, but also obtain the atmospheric extinction coefficient profile at different pitch angles at the same time. In addition, it can obtain the horizontal and slant atmospheric transmittance information at the same time, which has important application value for scenarios such as ensuring the safety of aircraft take-off and landing at airports.

[0034] (5) The object plane of any laser beam generated by the sheet laser unit described in this application intersects at a single point with the plane of the telescope and the image plane of the area array camera. This results in a very small detection blind zone, enabling the acquisition of atmospheric extinction coefficient and atmospheric transmittance information at different elevation angles. Furthermore, it allows for precise measurement and positioning of target objects at different distances. With the cooperation of a precision scanning platform and appropriate scanning step displacement, it can even image the target object, thereby achieving identification. In the current booming low-altitude economy, this design offers significant advantages in detecting low-altitude, slow-moving, and small targets. Additionally, this structure makes the lidar less susceptible to environmental interference, allowing it to continuously provide relatively accurate detection data even in environments with strong low-altitude interference. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a scanning lidar system detecting a target object in one embodiment.

[0036] Figure 2 This is a flowchart of a scanning lidar system detection method in one embodiment.

[0037] Figure 3 This is an image information diagram collected by a lidar system at a certain location in one embodiment.

[0038] Figure 4 for Figure 3 The LiDAR signal map corresponding to the data in the middle row (s).

[0039] In the picture:

[0040] 1. Laser unit; 2. Telescope; 3. Area array camera; 4. Data processing and control unit; 5. Scanning platform; 6. Target object. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In the description of the embodiments of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0042] Definitions:

[0043] A sheet laser unit: a system that generates continuous wave laser light in the form of thin, elongated stripes.

[0044] To solve the above problems, such as Figure 1 As shown, this application discloses a scanning lidar system, including:

[0045] The sheet laser unit 1 is used to emit sheet-shaped continuous wave laser towards the target object 6;

[0046] Telescope 2 is used to receive the reflected beam of the sheet-like continuous wave laser emitted by the sheet laser unit 1 after the interaction between the target object 6 and the sheet laser unit 1;

[0047] A planar array camera 3 is used to image the beam received by the telescope 2. The planar array camera 3 has a set number of rows in the elevation detection direction.

[0048] Scanning platform 5 is used to move the support frame as a whole.

[0049] The sheet laser unit 1 emits a sheet-shaped continuous wave laser to the target object 6, and the target object 6 interacts with the sheet-shaped continuous wave laser. The laser emitted by the sheet laser unit 1 has uniform intensity and is sheet-shaped.

[0050] The target object 6 can be the atmosphere, a low-speed, small target drone, a bird, etc.

[0051] Furthermore, if the target 6 is a low-speed, small-target UAV, the combination of scanning by the scanning platform and the sheet laser unit 1 can enable the search and discovery of low-speed, small-target targets in a large airspace.

[0052] Furthermore, if the target object 6 is the atmosphere, then by combining the scanning platform with the sheet laser unit 1, it is possible to obtain the atmospheric extinction coefficient profile over a large area, thereby enabling the measurement of horizontal and slant atmospheric transmittance. The obtained atmospheric extinction coefficient profile can also be used to determine the emission location of air pollution sources.

[0053] Traditional lidar for detecting low-speed, small targets or atmospheric extinction coefficients typically has a small laser divergence angle and receiving field of view, such as 0.1° x 0.1°, in order to achieve a longer detection range. Such a divergence angle results in low efficiency even when scanning. However, based on this solution, the laser divergence angle can be 0.1° x 20°, which, combined with an area array camera, allows for a larger detection range.

[0054] In detail, the system also includes a data processing and control unit 4 and a filter (not shown in the figure). The sheet-like continuous wave laser generated by the sheet laser unit 1 illuminates the target object 6. After the sheet-like continuous wave laser interacts with the target object 6 (which can be a soft target-atmosphere or a hard target-low, slow, small target), the resulting reflected signal is received by the telescope 2. After the background light is filtered out by the filter, the image is formed on the area array camera 3. The background light is light received by the telescope that is other than the same wavelength as the sheet-like continuous wave laser.

[0055] The data processing and control unit 4 is connected to the controlled end of the area scan camera 3, the sheet laser unit 1, and the controlled end of the scanning platform 5, respectively. The data processing and control unit 4 is used to read and process the image of the area scan camera 4, and at the same time control the opening and closing of the sheet laser unit 1 and control the scanning platform 5 to scan according to the set requirements.

[0056] This system can be applied to fields such as low-altitude economic flight support, industrial pollution source tracing, atmospheric transmittance measurement, and surveying.

[0057] In one embodiment, the positional relationship of the sheet laser unit 1, telescope 2, and area array camera 3 mounted on the support frame satisfies the following: the object plane containing any laser beam generated by the sheet laser unit 1 intersects at a single point with the plane where the telescope 2 is located and the image plane where the area array camera 3 is located, satisfying the Saxony imaging principle. This arrangement enables the system to have a large depth of field, thereby accurately obtaining the distance information of the target object 6.

[0058] In one embodiment, the sheet-like continuous wave laser generated by the sheet laser unit 1 has an angle in the vertical direction that is not less than the field of view angle in the vertical direction formed by the area array camera 3 and the telescope 2. This arrangement can ensure the utilization rate of the detector units on the area array camera 3, ensure the effectiveness of the detection data on the area array camera 3, improve the coverage in the single elevation angle direction, improve the detection efficiency, and ensure that the information of the target object 6 obtained by the lidar in a single detection is maximized.

[0059] Furthermore, the scanning platform is a horizontally rotating platform or a horizontally linear moving platform. In one embodiment, the scanning platform 5 rotates continuously horizontally, during which the sheet laser unit continuously scans the target object 6, acquiring relevant information characterizing the target object 6 at each scanning angle. The scanning platform 5 is a linear rotating platform. In one embodiment, the movement direction of the scanning platform 5 is perpendicular to the laser surface generated by the sheet laser unit 1. Based on the horizontal rotation of the platform, a large spatial area scanning and detection of the target object is achieved. The rotation angle range of the scanning platform can be selected at any angle. When rotating within a 360° range, the detection range of the lidar system is utilized to the maximum extent.

[0060] Assume the area array camera 3 has a resolution of N*M, i.e., N rows and M columns. The row number in any row of the image corresponds one-to-one with the elevation angle of the target object 6 in space, and the column pixel position in any row corresponds one-to-one with the distance of the target object 6 in space. The pixel value of the column pixel in any row represents the reflection intensity after the laser beam interacts with the target object 6, thus characterizing the volume and scattering coefficient of the target object 6 to some extent. Therefore, N rows represent N elevation angles, enabling the detection of targets within a certain elevation angle range at a given moment. Through scanning by the scanning platform 5, large-scale three-dimensional detection is achieved.

[0061] Furthermore, the scanning platform 5 moves intermittently or continuously over a set distance. In one embodiment, intermittent movement over a set distance ensures that detection occurs intermittently, and after detection, the platform moves to the next location, ensuring the accuracy of the detection data while enabling regional scanning detection. When the data processing and control unit 4 reads the image from the area scan camera 3, the image is associated with spatial orientation information. When the exposure time of the area scan camera 6 is fast enough, the movement speed can be very fast, allowing for continuous movement over the set distance.

[0062] The system has a relatively simple structure and a significant advantage in cost control compared to traditional lidar, making it more competitive in large-scale applications and market promotion. It has the ability to detect large-scale hard targets and the atmosphere simultaneously, meeting the cost requirements of more users and application scenarios, and promoting the popularization and application of lidar technology in more fields.

[0063] like Figure 2 As shown, this application discloses a scanning lidar detection method based on the above-mentioned scanning lidar detection system, including:

[0064] By utilizing the spatial location of the target object 6 at multiple known pitch angles and its corresponding pixel position information on the area array camera 3, the relationship between the pitch angle of the imaging field of view and the row index in the image acquired by the area array camera 3 is established.

[0065] By using the known distance information of the target object 6 and its corresponding pixel position information on the area scan camera 3, the relationship between the target distance and the column index in the image acquired by the area scan camera 3 is determined.

[0066] Read the two-dimensional image Q(x,y) generated by the interaction between the target object 6 and the sheet-like continuous wave laser at a certain moment, which is acquired by the area array camera. Here, x=1:N, y=1:M, and N and M correspond to the fact that the two-dimensional image has N rows and M columns, respectively.

[0067] Based on the calibration information, the lidar signal p(a,z) with any elevation angle a can be obtained from the two-dimensional image Q(x,y), where a = A:B, z = C:D, A and B correspond to the initial and final values ​​of the elevation angle, respectively; C and D correspond to the minimum and maximum values ​​of the detection distance, respectively.

[0068] Threshold processing is performed on the lidar signal p(a,z), and combined with the position information of the scanning platform 5, the azimuth, elevation and distance information of the target are obtained;

[0069] By combining the lidar equation, the lidar signal p(a,z) is processed, and combined with the position information of the scanning platform 5, the atmospheric extinction coefficient profiles for different pitch angles within the pitch angle range A to B are obtained.

[0070] In one embodiment, the lidar echo signal p(a,z) is subjected to thresholding, which includes fixed thresholding or adaptive thresholding.

[0071] In one embodiment, calculating the atmospheric extinction coefficient profile H(a,z) at the pitch angle from A to B includes:

[0072]

[0073] Among them, z m As a reference point, it lies between the minimum and maximum detection distances C and D, with boundary values ​​H(a,z). m );z m The value is continuously updated based on the abrupt change position of the lidar signal p(a,z), and the boundary value H(a,z) is... m The slope is obtained using the piecewise slope method;

[0074] In one embodiment, after calculating the atmospheric extinction coefficient profile at pitch angles A to B, the method further includes:

[0075] The atmospheric transmittance at different pitch angles is obtained by calculating the atmospheric extinction coefficient profile, and the spatial location information of the atmospheric pollution emission source is determined by the atmospheric extinction coefficient profile.

[0076] In one embodiment, after calculating the target object 6 information at different distances under different pitch angles, the method further includes:

[0077] The scanning platform 5 moves a certain distance, detects the next azimuth angle, updates the target information, and returns to read the two-dimensional image Q(x,y) generated by the interaction between the target and the sheet laser at a certain moment, until all target information 6 within the target range is obtained.

[0078] Based on the above system and method, at a certain azimuth angle (corresponding to a certain position of the scanning platform 5), the sheet laser unit 1 emits a sheet-like continuous wave laser into the target scene. After the sheet-like continuous wave laser interacts with the target object 6, the reflected beam is received by the telescope and finally imaged on the area array camera 3. The data processing and control unit 4 reads the two-dimensional digital image Q(x,y), as shown in the figure. Figure 3 As shown.

[0079] After calibration, the row information of the two-dimensional digital image Q(x,y) corresponds to the pitch angle information of target object 6, and the column information of the two-dimensional digital image Q(x,y) corresponds to the distance information of target object 6. Figure 3 As can be seen, there is a bright spot at the "s" line and the "k" distance. The lidar signal p(s,z) for the "s" line at that pitch angle is extracted, as follows: Figure 4 As shown, threshold processing is performed on the lidar signal p(s,z). For example, if the threshold is set to 25000, a strong abrupt change signal can be obtained at a distance of 50. Combined with the actual target scene, the target at the pitch angle, azimuth angle, and distance can be detected and determined. Following the same method, hard targets at all pitch angles from A to B can be detected and discovered. It can be seen that the present invention can achieve target detection at large pitch angles with a single detection. Combined with the continuous movement of the scanning platform 5, hard targets in a large airspace can be detected and discovered.

[0080] Similarly, for Figure 3 The lidar signal p(s,z) corresponding to row "s" in the middle is processed. Since there is a sudden signal at a distance of 50, the reference point z... m=50, observe the signal characteristics of p(s,C:50) and p(s,50:D), that is, whether their change with distance is a straight line or approximately a straight line, and select the slope of p(s,C:50) or p(s,50:D) as the boundary value H(s,50), and then substitute them into the following formula:

[0081]

[0082] The atmospheric extinction coefficient profile H(a,z) at this pitch angle can be obtained. Using the same method, the atmospheric extinction coefficient profiles at all pitch angles from A to B can be obtained.

[0083] In one embodiment, obtaining atmospheric transmittance at different pitch angles from the calculated atmospheric extinction coefficient profile includes: obtaining the atmospheric transmittance at different pitch angles from the calculated atmospheric extinction coefficient profile according to the following formula:

[0084]

[0085] As can be seen, the present invention can obtain the atmospheric extinction coefficient profile at a large pitch angle with a single detection, and then obtain the horizontal and oblique atmospheric transmittance; combined with the continuous movement of the mobile platform 5, it can detect the atmospheric extinction coefficient profile of a large airspace. The three-dimensional data of the atmospheric extinction coefficient can provide a basis for tracing the emission sources of pollution.

[0086] In the description of this specification, references to terms such as "some embodiments" or "example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0087] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A scanning lidar system, characterized in that, include: A sheet laser unit is used to emit sheet-shaped continuous wave lasers toward a target object; A telescope is used to receive the reflected beam of light after the target object interacts with the sheet-like continuous wave laser. An area array camera is used to image the beam received by the telescope, and the area array camera has a set number of rows in the elevation detection direction; Support frame, used to fix the plate laser unit, telescope and area array camera; The scanning platform is used to move the support frame as a whole. By using the known spatial location of the target object at multiple pitch angles and its corresponding pixel position information on the area scan camera, the relationship between the pitch angle of the imaging field of view and the row index in the image acquired by the area scan camera is established; by using the known distance information of the target object and its corresponding pixel position information on the area scan camera, the relationship between the target distance and the column index in the image acquired by the area scan camera is determined. Read the two-dimensional image Q(x,y) generated by the interaction between the target object and the sheet-like continuous wave laser at a certain moment, which is acquired by the area array camera, where x=1:N, y=1:M, and N and M correspond to the two-dimensional image having N rows and M columns, respectively; Based on the calibration information, the lidar signal p(a,z) with an arbitrary elevation angle a is obtained from the two-dimensional image Q(x,y), where a=A:B, z=C:D, A and B correspond to the initial and final values ​​of the elevation angle, respectively; C and D correspond to the minimum and maximum values ​​of the detection distance, respectively. Threshold processing is performed on the lidar signal p(a,z), and combined with the position information of the scanning platform, the azimuth, elevation and distance information of the target are obtained; By combining the lidar equation, the lidar signal p(a,z) is processed, and the atmospheric extinction coefficient profiles for different pitch angles within the pitch angle range A to B are obtained by combining the position information of the scanning platform.

2. The scanning lidar system according to claim 1, characterized in that, The positional relationship of the sheet laser unit, telescope, and area array camera mounted on the support frame satisfies the following: the object plane containing any laser beam generated by the sheet laser unit intersects at a point with the plane where the telescope is located and the image plane where the area array camera is located, satisfying the Saxony imaging principle.

3. The scanning lidar system according to claim 1, characterized in that, The angle of the sheet-like continuous wave laser emitted by the sheet laser unit in the vertical direction is not less than the field of view angle in the vertical direction formed by the area array camera and the telescope.

4. A scanning lidar system according to claim 1, characterized in that, The scanning platform is a horizontal rotating platform or a horizontal linear moving platform.

5. A scanning lidar system according to claim 1, characterized in that, The system also includes a data processing and control unit and a filter; the filter is used to filter out background light received by the telescope that is not of the same wavelength as the sheet continuous wave laser; the data processing and control unit is connected to the controlled end of the area array camera, the sheet laser unit, and the scanning platform, respectively; the data processing and control unit is used to read and process the image of the area array camera, and at the same time control the opening and closing of the sheet laser unit and control the scanning platform.

6. A scanning lidar detection method, characterized in that, include: By using the known spatial location of the target object at multiple pitch angles and its corresponding pixel position information on the area scan camera, the relationship between the pitch angle of the imaging field of view and the row index in the image acquired by the area scan camera is established; by using the known distance information of the target object and its corresponding pixel position information on the area scan camera, the relationship between the target distance and the column index in the image acquired by the area scan camera is determined. Read the two-dimensional image Q(x,y) generated by the interaction between the target object and the sheet-like continuous wave laser at a certain moment, which is acquired by the area array camera, where x=1:N, y=1:M, and N and M correspond to the two-dimensional image having N rows and M columns, respectively; Based on the calibration information, the lidar signal p(a,z) with an arbitrary elevation angle a is obtained from the two-dimensional image Q(x,y), where a=A:B, z=C:D, A and B correspond to the initial and final values ​​of the elevation angle, respectively; C and D correspond to the minimum and maximum values ​​of the detection distance, respectively. Threshold processing is performed on the lidar signal p(a,z), and combined with the position information of the scanning platform, the azimuth, elevation and distance information of the target are obtained; By combining the lidar equation, the lidar signal p(a,z) is processed, and the atmospheric extinction coefficient profiles for different pitch angles within the pitch angle range A to B are obtained by combining the position information of the scanning platform.

7. The scanning lidar detection method according to claim 6, characterized in that, Obtaining the atmospheric extinction coefficient profile within the angular range from pitch angle A to B includes: obtaining the atmospheric extinction coefficient profile for different pitch angles within the angular range from pitch angle A to B according to the following formula: With <z m z≥z m Among them, z m Let H(a,z) be the reference point, located between the minimum and maximum detection distances C and D. The boundary value at the reference point is H(a,z). m );z m The value is continuously updated based on the abrupt change position of the lidar signal p(a,z), and the boundary value H(a,z) is... m） The slope is obtained using the piecewise slope method.

8. A scanning lidar detection method according to claim 6 or 7, characterized in that, Based on the calculated atmospheric extinction coefficient profiles at different pitch angles, the following is also included: The atmospheric transmittance at different pitch angles is obtained by calculating the atmospheric extinction coefficient profile, and the spatial location information of the atmospheric pollution emission source is determined by the atmospheric extinction coefficient profile.

9. A scanning lidar detection method according to claim 8, characterized in that, The method of obtaining atmospheric transmittance at different pitch angles by using the calculated atmospheric extinction coefficient profile includes: obtaining the atmospheric transmittance at different pitch angles from the calculated atmospheric extinction coefficient profile according to the following formula: 。 10. A scanning lidar detection method according to claim 8, characterized in that, After calculating target information at different pitch angles, the process also includes: The scanning platform moves a certain distance, detects the next azimuth angle, updates the target information, and returns to read the two-dimensional image Q(x,y) generated by the interaction between the target and the sheet-like continuous wave laser at a certain moment, until all target information within the target range is obtained.

Images